Substrate processing liquid, substrate processing method, and substrate processing apparatus

Abstract

In the present invention, a substrate processing liquid includes an auxiliary agent which is added to a solution in which a sublimable substance is dissolved in a solvent, to thereby disperse particles of the sublimable substance, the amount of which exceeds the solubility, in the solution. In the substrate processing liquid, the particles of the sublimable substance, the amount of which exceeds the solubility, are uniformly dispersed and dissolved in the solvent. Therefore, the amount of sublimable substance to be supplied onto a pattern formation surface of a substrate is larger than that in the conventional technique and a large amount of sublimable substance (solid phase) exists inside a pattern. As a result, it is possible to effectively suppress the solvent from remaining between the patterns and perform sublimation drying in a state where the patterns are firmly held by the sublimable substance (solid phase).

What is claimed is: 
     
         1 . A substrate processing liquid used for removing a liquid on a substrate having a pattern formation surface, comprising:
 a sublimable substance;   a solvent that dissolves the sublimable substance; and   an auxiliary agent that is added to a solution in which the sublimation substance is dissolved in the solvent to disperse particles of the sublimation substance exceeding the solubility in the solution.   
     
     
         2 . The substrate processing liquid according to  claim 1 , wherein
 the auxiliary agent is a crystallization inhibitor for inhibiting crystallization of the sublimable substance in the solution.   
     
     
         3 . The substrate processing liquid according to  claim 1 , wherein
 the sublimable substance is cyclohexanone oxime, and   the auxiliary agent performs pH adjustment of the solution so that the zeta potential of the sublimable substance in the solution becomes negative.   
     
     
         4 . The substrate processing liquid according to  claim 3 , wherein
 the auxiliary agent is aqueous ammonia.   
     
     
         5 . A substrate processing method, comprising:
 (a) preparing the substrate processing liquid according to  claim 1 ;   (b) supplying the substrate processing liquid prepared in the operation (a) onto a front surface of a substrate on which a pattern is formed, to thereby form a liquid film of the substrate processing liquid on the front surface of the substrate;   (c) solidifying the liquid film of the substrate processing liquid, to thereby form a solidified film of the sublimable substance; and   (d) sublimating the solidified film, to thereby remove the solidified film from the front surface of the substrate.   
     
     
         6 . The substrate processing method according to  claim 5 , wherein
 the operation (a) includes storing the substrate processing liquid in a storage bath to which ultrasonic vibration is applied.   
     
     
         7 . The substrate processing method according to  claim 6 , wherein
 the operation (a) has   (a-1) preparing a supersaturated solution of the sublimable substance;   (a-2) depositing the sublimable substance from the supersaturated solution;   (a-3) purifying the substrate processing liquid by adding the auxiliary agent to a solution in which the deposited sublimable substance is dissolved in the solvent; and   (a-4) replenishing the storage bath with the substrate processing liquid purified in the operation (a-3).   
     
     
         8 . The substrate processing method according to  claim 7 , wherein
 the operation (a-3) includes cleaning the deposited sublimable substance before dissolving the deposited sublimable substance in the solvent.   
     
     
         9 . The substrate processing method according to  claim 7 , wherein
 the operation (a-1) is performed in an ultrasonic bath to which ultrasonic vibration is applied;   the operation (a-2) is performed by stopping application of an ultrasonic wave to the ultrasonic bath storing therein the supersaturated solution; and   the operation (a-3) is performed by resuming application of ultrasonic vibration to the ultrasonic bath.   
     
     
         10 . The substrate processing method according to  claim 6 , wherein
 the operation (b) includes discharging the substrate processing liquid to the front surface of the substrate from a nozzle, to thereby supply the substrate processing liquid onto the front surface of the substrate, while applying ultrasonic vibration to the substrate processing liquid inside the nozzle.   
     
     
         11 . The substrate processing method according to  claim 10 , wherein
 the operation (b) includes feeding the substrate processing liquid to the nozzle from the storage bath while applying ultrasonic vibration to the substrate processing liquid.   
     
     
         12 . A substrate processing apparatus, comprising:
 a storage part configured to store therein the substrate processing liquid according to  claim 1 , and   a processing liquid supply part configured to supply the substrate processing liquid stored in the storage part onto a front surface of a substrate on which a pattern is formed.